The invention relates to improvements in apparatus for testing rod-shaped articles of the tobacco processing industry, and more particularly to improvements in sealing elements which are utilized in such apparatus to convey a testing fluid (for example, atmospheric air) from a fluid source into an end of an article to be tested or from an article to be tested to a monitoring device for testing fluid. Still more particularly, the invention relates to improvements in sealing devices of the type disclosed in commonly owned U.S. Pat. No. 4,429,567 granted Feb. 7, 1984 to Koch et al. for "Apparatus for testing cigarettes or the like". The disclosure of this patent is incorporated herein by reference.
The patent to Koch et al. discloses sealing elements wherein an end wall of a tubular body of elastomeric material has an opening and can be engaged by the end face of an article to be tested so that a testing fluid can flow from the interior of the tubular body into the article or in the opposite direction. The external surface of the end wall is surrounded by an annular elastic lip which is flexed radially inwardly against the peripheral surface of the article to be tested while the end face of such article bears against the end wall, i.e., in response to inward displacement of the end wall by the article to be tested. A drawback of presently known sealing elements is that their useful life is rather short, often because the relatively sharp edges of tubular wrappers of articles which are caused to bear against the external surface of the end wall are likely to cut into and/or otherwise damage the end wall and/or the surrounding lip.